The Data Management Core (DMC) is the storage for all relevant research data collected in the program project. We will: Maintain a database containing all instruments administered and derived measures as diagnoses and Fagerstrom and ancillary variables on smoking consumption; Provide data entry and cleaning programs at the participating sites and harvest data on a regular basis; Maintain a pedigree database containing all families entered into the study; Maintain data sets containing the genotypic data from the molecular genetics and biological marker companies; Provide well-documented, cleaned copies of all data sets to investigators on a regular basis; and maintain a WEB site for all investigators. We will provide identical entry software at each site, so that entry and cleaning will be local. The SSAND and FHAM items will be entered using a SAS based on a PC. Entry screens will be identical to the clinical interviews and the complex pattern of identifying information (other than the study ID) is entered into this system. We will provide another program (DIGGER 2000) for the site to track subjects contacts and contain identifying information. We will establish a Home Page on the St. Louis Central computer for the study. Access to this page will require a sign-on and password. All progress reports, etc. are written automatically as HTML documents., software for data entry, and SAS masterfile can be downloaded using NESTSCAPE to computers at participating sites. We will place copies of the instruments and forms given on our WEB site. During the next five years, our emphasis will be to provide complete documentation on all aspects of the project-study design, diagnostic algorithms, SSAND specifications, Editor's Notes, a Codebook for all variables, etc.